Rav Yosef (who gave the maximum distance between two trees in a vineyard as less than eight Amos) was not impressed with Abaye's Kashya (from the Mishnah in Kil'ayim), because he relied on an incident that took place in Dura di'Re'usa which literally means 'town of shepherds'.

When a man purchased three trees with a space of less than eight Amos between each two trees Rav Yehudah ruled that the seller should make sure that there was sufficient room for the ox and its accessories to pass.

Rav Yosef did not understand what he meant, until he learned a Beraisa which to explain the Mishnah in 'Lo Yachpor', which forbids a person to plant a tree within four Amos of his friend's pit attributes the four Amos to the distance that is required to work the vineyard.

In spite of Rebbi Meir and Rebbi Shimon, who, in the very same Mishnah in Kil'ayim, permit the planting of seeds in a vineyard where there is a space of eight Amos between the rows (like Rav Yosef) Abaye queries Rav Yosef on the basis of the Tana Kama, because his ruling is based on an incident, which carries a lot of weight Halachically.

We just cited the Mishnah where Rebbi Shimon (and Rebbi Meir) gives the maximum distance of one row of vines and the other as less than eight Amos. We know that the minimum Shi'ur is four Amos from another Mishnah in Kil'ayim, where Rebbi Shimon specifically states that a vineyard whose rows are planted less than four Amos apart, is not a vineyard.

The Chachamim disagree with him however. They consider it a vineyard nonetheless because the excess trees stand to be removed (and we have a principle 'Whatever stands to be uprooted is considered as if it has already been uprooted').

We know that the minimum Shi'ur of the Tana Kama of Rebbi Yehudah (in the Mishnah in Kil'ayim) is eight Amos from a Sevara; if the minimum Shiur of Rebbi Shimon is half the amount of the maximum Shiur, presumably the same will be the case according to the Chachamim.

According to Rava the minimum distance that is permitted between two rows of vines in a vineyard is four Amos, and the maximum sixteen.

Rava adopts the two extremes (like the smallest Shi'ur of Rav Yosef) based on the incident in Dura de'Reusa, and the largest of Rav Nachman (whom he himself quoted earlier) based on the incident in Tzalmon.

Rava is following the opinion of the Chachamim (the Tana Kama of Rebbi Yehudah), who argue with Rebbi Shimon with regard to the maximum Shi'ur, but not, in his opinion, with regard to the minimum Shiur.

In the Beraisa that we quote in support of Rava, the Tana grants someone who purchases three trees, the land in between and the trees. By 'trees' he means saplings.

He then goes on to cite three cases where the purchaser of three trees does not acquire the land; 1. where the trees have been planted within four Amos of each other; 2. Where they have been planted more than sixteen Amos apart; 3. where he purchased the trees independently (in two or three separate sales).

Rebbi Yirmiyah asks whether one measures the above distances from the narrow part of the tree or from the wide part. This She'eilah does not refer to the trunk up to the point where the branches grow or to the tips of the branches respectively, but to the trunk of the tree after it has risen above the roots and the foot of the trunk next to the roots (where it is much wider).

Rav Gevihah from bei Kasil resolves this She'eilah from a Mishnah in Kil'ayim, which rules that one measure a grafted vine ([see Rabeinu Gershom, also Tosfos DH 'ha'Rekuvah'] in connection with the minimum four-Amah space that determines what is a vineyard) from the knot in the vine (not lower down, where it is very wide, and not higher up, where it is narrow), but from the middle. And that is how one measures all trees in this regard.

He then asks what the Din will be in a case where someone purchased a tree with three 'Badei Ilan'. This cannot refer to someone who purchased three branches, one on each of three trees, and the She'eilah is whether we go after the branches (in which case he acquires the land too), or after the tree (and he does not acquire the land) because it would be obvious that in such a case, since the owner retains the majority of the branches, he did not sell the purchaser the land.

The She'eilah therefore is where he sold him a tree with three low branches that are four Amos apart, and that had become covered by earth in a way that they now resemble three trees. Do we go after the tree (seeing as all the branches feed from it [in which case he will not acquire the land), or after the branches (and he will acquire it).

Once again, Rav Gevihah solves the She'eilah from a Mishnah in Kil'ayim, where, in a case where someone bends three branches of three vines and transplants them in the ground, after they have taken root, Rebbi Eliezer b'Rebbi Tzadok rules that as long as there is a distance of between four and eight Amos (like Rebbi Meir and Rebbi Shimon) between each 'vine', it is considered a vineyard comprising six vines.

What connects Rebbi Yirmiyah's current She'eilah with Rebbi Eliezer b'Rebbi Tzadok's Halachah is the fact that in both cases, the respective branches all feed from the same root (Yet they have the in of independent trees).

The minimum number of vines required to constitute a vineyard is five vines ('two opposite two, and the fifth going out like a tail').

Rav Papa asks what the Din will be if Reuven sells Shimon two trees in his field and one on the border. Shimon might not acquire the ground because the third tree is not completely in the same domain as the other two.

Then he asks what the Din will be if he sells him two trees in his field and the third one in Levi's field. For this She'eilah to have any meaning, Rav Papa must assume in the previous She'eilah that the border is not considered a division, and that the purchaser does acquire the land in between. Therefore he suggests that, in this case, where the third tree really is in a different domain, perhaps he does not acquire it.

The outcome of the two She'eilos is 'Teiku'.

Rav Ashi asks whether a water-pit, a stream, a road or a cluster of palm-trees will divide the three trees. By a road he means a small street of between four and sixteen Amos (because one of sixteen Amos wide [a Reshus ha'Rabim] is certainly considered a division.

The significance of the sequence of ...

... Rav Papa's She'eilos followed by those of Rav Ashi is that the latter presumes that the former cases are not considered a division.

... Rav Ashi's four She'eilos follows the same pattern; each ensuing She'eilah presumes that the previous case is not considered a division.

We query the She'eilah that Hillel (not Hillel ha'Zaken) asked Rebbi regarding a cedar-tree that grew among the three trees that Shimon bought on the grounds that Shimon acquired the ground at the time of the sale, in which case the cedar that subsequently grew there, grew in his ground.

Hillel's She'eilah must therefore have been what the Din will be if there was a cedar in the field at the time of the sale ...

... to which Rebbi replied that the purchaser acquired both the ground and the cedar (as we learned on the previous Amud 'Kanah Karka ve'es ha'Ilanos' [see Rashbam there and Ritva here]).

According to Rav, Shimon acquires the ground even if the three trees are growing in a straight row. According to Shmuel however they must be growing in the shape of a triangle ...

... because otherwise, it is easy for Reuven to plow the space in between them (in which case, he would not have automatically sold the ground with the trees).

If, as we just concluded, the criterion for acquiring the ground is the fact that it is difficult for the owner to plow the ground in the middle, we suggest that if Shimon purchases three large thorn-bushes from Reuven, he will also acquire the ground, taking into account the difficulty of plowing in between the bushes even if they are growing in a straight row, seeing as, either way, Reuven will not plow there, for fear of getting scratched by the thorns.

We refute this suggestion however, on the grounds that the Sevara of not being able to plow in between the trees is only one of two criteria for acquiring the ground; the other one being that the trees are valuable (which thorn-bushes are not).

Discussing the sale of certain limbs of a large species of animal (a cow or a bull), our Mishnah rules that if Reuven sells Shimon ...

... the head the legs are not automatically included in the sale, and vice-versa.

... the lungs the liver is not automatically included in the sale, and vice-versa.

Local custom however overrides these rulings.

Regarding a small species of animal however (i.e. a sheep or a goat), if Reuven sells Shimon ...

... the head the legs will automatically be included in the sale, but not vice-versa.

... the lungs the liver will automatically included in the sale, but not vice-versa.

The Tana then lists four Dinim concerning the validity of a sale. If Reuven sells Shimon ...

... superior wheat, and it turns out to be inferior Shimon has the right to retract.

... inferior wheat, and it turns out to be superior Reuven has the right to retract. (Note, that Ona'ah with regard to the seller means that he is unaware of the selling-price of the article).

... what he promised him, be it inferior or superior wheat neither has the right to retract.

... Shachmasis (a reddish color wheat) and it turns out to be white, or vice-versa both have the right to retract.

If Reuven sells Shimon olive-trees, which turn out to be sycamore, or vice-versa this belongs to the last category, and both parties have the right to retract.

The previous case (as well as where he sold him wine and it turned out to be vinegar) belongs to this category too, and not to the first category in the Mishnah because whenever both articles are saleable, only it is a matter of personal preference, it becomes a matter of Mekach Ta'us, rather than Ona'ah.

The fact that the Tana mentions the number 'four' comes to stress that there are four categories (no less, no more) and not to preclude anything in particular (as it usually does).

The first two cases (superior and inferior) is not one of Mekach Ta'us (a false sale), but of Ona'ah. The party that may retract is always the one that been cheated.

The distinction between this Din of Ona'ah and a regular case, where only the price is involved is that whereas in the latter case, the person who was 'cheated' may reclaim the difference in price (as Rava rules in Perek ha'Zahav), in the former, he has the additional right to cancel the sale.

In a case where Reuven gave Shimon ...

... inferior wheat, as he promised him, but then the price of wheat went down, we might have thought that Shimon can retract because he can argue that he really wanted to buy superior wheat, only he referred to the goods as 'inferior', because that is the natural thing for a purchaser to do.

... superior wheat, as he promised him, but then the price of wheat went up, we might have thought that Reuven can retract because he can argue that he really intended to sell inferior wheat, only he referred to the goods as superior, because that is the natural thing for a purchaser to do.